I have a cheap hdtv. when i connect my macbook to it it doesn't get a signal (via mini dvi to hdmi) until i click "detect displays" on my laptop, then "gather windows," then when i set the display to the proper resolution (720) the image appears on my tv without a problem. I just got a mac mini, and since i don't have two monitors I cannot use this trick. I get no image on my tv. Any suggestions?